


How To Build Your Triad

by DeiStarr



Series: My Lives As Fate's Chew-Toy [9]
Category: Harry Potter - J. K. Rowling
Genre: Accidental Relationship, Bedtime Stories, Boys In Love, Courting Rituals, Declarations Of Love, Developing Relationship, Dialogue Heavy, Didn't Know They Were Dating, Except James Doesn't Realise He's Pining, F/M, Falling In Love, Fluff and Humor, Idiots in Love, Inspired by How I Met Your Mother, Lily Evans Has The Only Brain Cell, Love Triangles, M/M, Matchmaking, Multi, Mutual Pining, Oblivious James Potter, Pining Sirius Black, Polyamory, Polyamory Negotiations, Pureblood Culture (Harry Potter), Romantic Fluff, Sort Of, Story within a Story, Unreliable Narrator
Language: English
Status: In-Progress
Published: 2020-10-25
Updated: 2020-10-25
Packaged: 2021-03-08 21:33:55
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,478
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27193156
Author URL: https://archiveofourown.org/users/DeiStarr/pseuds/DeiStarr
Summary: How To Build Your Triad(In Ten (Not-So) Easy Steps)ByLily Evans-Potter-Black & Sirius Potter-Black[{Shut up and look pretty, James.}]Sirius tells baby Harry how his parents' got together as a bedtime story.Lily helps.{James doesn't get to talk; thedenseone didn't do any of the work.}[Silence in the peanut gallery, Moony.]
Relationships: James Potter/Lily Evans Potter, Sirius Black/James Potter, Sirius Black/James Potter/Lily Evans Potter, Sirius Black/Lily Evans Potter
Series: My Lives As Fate's Chew-Toy [9]
Series URL: https://archiveofourown.org/series/1594597
Comments: 3
Kudos: 60
Collections: My Lives As Fate's Chew Toy





	How To Build Your Triad

**Author's Note:**

> This is just something fun to help me get back into the swing of writing in this series again, after being out for so long. The chapters won't be very long; it's why there are so many, since the story isn't particularly long. I just thought it was cute. 
> 
> ***IMPORTANT!***
> 
> Since changing the colour of the font doesn't work for posting, comments by characters are written in different types of parentheses. 
> 
> {Sirius Potter-Black's comments are in this type of parentheses}
> 
> [Lily Evans-Potter-Black's comments are in this style]
> 
> 《James Potter-Black's are in this one》
> 
> [{This is Lily and Sirius talking together}]

_{So, you may be wondering just how this whole thing came about. Ours is a pretty unusual relationship, after all.}_

_{Hush Moony, just because he's a baby doesn’t mean he can’t understand; my little puppy is a **genius!** }_

_{No, I don’t see anything wrong with calling my child a puppy, why would I? **Pffft!** I'm not going to give him a **complex** , Moony; now shut your furry arse up and let me tell the story!}_

_{Anyway, pup, sit still and let your Papá tell you a-a-a-a-all about it!}_

_{It all started on an ordinary enough day._

_Sirius Black was in the library, studying...}_

_{Yes, I **do** study sometimes; **shut up,** Moony! No, I don’t just mean for pranking– oh, **come on!** **Moooo-neeeeey!** Just let me tell the story, alright?}_

**_{Ahem.}_ **

_{Right; as we were discussing, this **absolute paragon** of **manliness** and **virtue** and **good-study-habits(!)** was attending to his education as he always did-}_

_[Always? **Really,** Sirius?]_

_{Oh come on, Lils; not **you** too! What is this; **“Everybody pick on Sirius”** time?!}_

_[Oh hush, you big baby. You **love** it.]_

_{...That's **not** the point. I'm trying to tell our pup a story!}_

_[Okay, fine. But you probably won't tell it right if I leave you to do it on your own, so I'll help.]_

**_{...Fine.}_ **

_[Don't sulk, Love. You **know** you tend to get carried away a bit.]_

_{Alright, **alright**.}_

_{So, Sirius Black was studying in the library; when suddenly, **an actual goddess-** }_

**_[Sirius!]_ **

_{Ah! You're laughing! You can't complain when I made you laugh!}_

_[Sirius, be **serious**.]_

_{I always am!}_

_{...You did that on purpose, didn't you?}_

_[...Ask me no questions...]_

_{...I knew I fell in love with you **for a** **reason** , Lily Evans-Potter-Black!}_

* * *

It started one day in Hogwarts, when Lily Evans joined Sirius Black at a table in the library.

Now, at this point, Lily had been dating Sirius' best friend; James Potter, for a few months.

So having her come and join Sirius was... not _unusual_ ; but usually James was with either her or Sirius when she did. So it was a bit different for her to seek him out alone. 

They studied quietly for a little while before Lily broke the silence with an abrupt, unexpected statement.

“We should go on a date.”

Sirius stared.

“What?”

She raised an unimpressed eyebrow at him.

“I _said_ ,” she repeated slowly. “That we should. _Go. On. A. Date.”_

 _“We?”_ Sirius asked, utterly bewildered. “As in, _you_ and _me?_ ”

She nodded.

Anger flared inside Sirius; outrage burning white-hot.

Lily had seemed frustrated with James for a while now, even though he had no idea why she was upset. But the thought that she would _cheat_ on him just to get back at him for something... Sirius was incredibly disappointed in her. Apparently, he'd been a fool to think she could ever be good enough for his best friend.

“In case you've forgotten, _Evans_ ,” he sneered. “You happen to be _my best mate's girlfriend._ So, _no._ I _do not_ want to go on a date with you; and you'd better have a good explanation for asking if you don't want me to tell James about this!”

Lily crossed her arms and scowled at him.

“I _know_ about you and James,” she told him, a little angry herself. “I've seen the way you two look at each other when you think no one else is watching! And I am not going to be reduced to a _walking womb_ in _your_ epic love story; so if this is going to work out, it needs to involve _all three of us!”_

Sirius was stunned into silence.

Then the shame crept in, and he dropped his gaze to the table.

“You're wrong,” he said quietly. “That's not- We aren't-“

He huffed, frustrated. “James doesn’t feel that way about me.”

A bitter smile twisted his lips.

“I can guarantee you that he's _never_ thought of me that way. Even if he ever did, he'd never act on it; just brush the idea aside and forget about it. He's the last Potter, after all; the only one who can continue his bloodline – and he actually _likes_ his family. So,” he said, looking back up at her. “I'll just keep on keeping my feelings to myself, and be grateful for his friendship.”

Lily’s lips parted in surprise as he spoke.

He shrugged. “I _get_ it, you know? The Potters are _awesome_. I've always known I didn't have a chance, so I've never bothered to hope for anything more than being his best friend. Even if I can't help _looking_ , sometimes.”

He flushed. “Sorry I gave you the wrong idea.”

Lily shook her head.

“You're telling the truth,” she marvelled. “You both really have _no idea_ , do you?”

A frown creased his forehead.

“What do you mean?”

She sighed, leaning forward to put her elbows on the table.

“Whether he’s consciously acknowledged it or not, James feels the same way about you. It's written all over his face in the way he looks at you; it was actually one of the reasons I had such a hard time believing he _actually liked_ me.”

He opened his mouth to object, but Lily held up a hand to stop him.

“I know,” she added hastily. “He really _does_ love me; that’s why I’m dating him, even though I thought he was dating you as well.”

She shrugged. “The whole point of my coming here to talk to you was to say that I wanted us to date as well; because if there are going to be three people in this relationship, I'd prefer for _all_ of us to be equally involved and equally in love with each other.”

“What are you-"

“Triad marriages are a thing, right?”

Sirius stared again, his heart pounding thunderously in his chest.

“I mean, three people who all love one another can get bonded... it's an old pureblood custom I read about a couple of years ago. There are even ways to ensure that any children born from those unions will belong to all three partners equally... I'm surprised you don't know of it.”

“ _I_ know about it,” he said, his voice coming out hoarse. “I just didn't think _you_ did. Or that you'd ever be willing to do it if you did. It's considered Dark Magic, after all.”

She wrinkled her nose. 

"Yeah, that part didn't really make sense to me. _But_ ," she waved away the explanation he started to offer. "You can get into all the technical aspects of the classification later - I'll _definitely_ want to grill you for more information in a bit - but for now let's just focus on this conversation." 

_"So,"_ she redirected. "You didn't think I'd be interested in being part of a triad. That doesn't explain why you wouldn't just try to get James to consider someone else who _would_ , or start dating him and let him come to that conclusion himself."

He offered her a wry grin.

“James was smitten with you since first year, so your opinion was the one that was going to matter. Which is why I never bothered trying.”

Lily laughed.

“Well, since I thought you and James were already together, I never would have agreed to date him if I didn't.” Her eyes softened as she watched him. “I assumed that this was what I was getting into from the beginning, and I was starting to get frustrated that the two of you were taking so long to tell me.”

_“Oh.”_

Suddenly, the bad mood Lily had been in recently made a _lot_ more sense.

She grinned at him. “So, I guess you'll be coming along on all of our dates from now on, alright?”

A bark of laughter escaped him; disbelieving yet joyous. He'd never felt hope like this before, and it was a little overwhelming.

“ _We_ still need to spend time together, one on one, Sirius,” she added. “A Triad Bonding only works if _all_ three partners are equally committed to each of their bond-mates. You and I both love James, and he loves both of us; so we need to start working on the relationship between the two of us as well.”

“Yeah, I- yeah.” It still didn't feel real to Sirius. “I sort of forgot that part.”

She snorted. “I guess I should have known that I was going to have to be the smart one in this relationship.”

Sirius gasped.

“ _Evans!_ You _wound_ me!” He flailed dramatically.

She laughed again, clear and bright and happy.

It was the start of a beautiful relationship. 

* * *

_[It really was.]_

_{Yeah I remember; you were **very** **impressed** that I was being **so noble** about my feelings!}_

_[…I regret telling you about that.]_

_{No, you don't.}_

_[I do. You get unbearably **smug** over it!] _

_{Uh-uh, no you don't.}_

_[No, I **do**. I really, really do.] _

_{ **No** you do-}_

_..._

**_[{Shut up, Moony!}]_ **

**Author's Note:**

> I'll be adding a three-part E-rated sequel after this featuring the Triad's wedding day, deciding to have a baby, and welcoming baby Harry to the world.
> 
> If there are any more side stories you want to see in this verse (or any verse I write, honestly), feel free to drop a request in the comments. I'll whip something up for you. :)


End file.
